Ignition controller



Feb. 18, 1941. J. 1.. ARTHUR IGNITION CONTROLLER Filed Aug. 51, 1938 INVENTOR dame-.3 L. filer/we Patented Feb. 18, 1941 PATENT OFFICE 2,232,301 IGNITION CONTROLLER;

James L. Arthur, Anderson, 1nd,, assignor to General Motors Corporation, Detroit, Mich., a corporation of Delaware Application August a1, 1938, Serial No. 227,668

-5 Claims. (01. 123-117) This invention relates to ignition timer control mechanism for internal combustion engines, and particularly to installations incorporating an automatic speed governor mechanism, either used 5 alone, in addition to, or in combination with the usual manual throttle'control, Y

The automatic ignition timer control of internal combustion engines inmain, operates upon the principle of differentials of pressure, manifest at some point intlie fuel induction pipe of an internal combustion engine as related to the atmospheric pressure out'sideof the fuel intake system. The point of vacuum take-off fromthe fuelinduction pipe is usuallyat a point near the edge of the throttle valve, and its connection with the motive unit so controlled either directly or indirectly by movementof the throttle valve, that the motive unit of the timer shift mechanism onerates underpredet'ermined conditions, and/or 'at predetermined relations of parts, to efiect a relative retard of spark timing during engine starting, and engine idling, and thence to effect a predetermined amount of timer shiftinaccordance with prescribed engine operation. Such a system depends forits' effectiveness more or less upon the pressure potential immediately posterior to the throttle valve, and in some instances to the pressurepotentials' on both sides of the throttle valve, and also takes into account whether the throttle valve be but slightly open or wide open. I e I .Incertain characters of installations, it becomes desirable to interpcsean automatic speed governing mechanism or other auxiliary device in the intake fuel passage between the conventional throttlevalve and'the cylindersof the internal combustion motor. In certain of those installations, the pressure potentials are disturbed to the point that they canno longer be relied upon to provide a dependable initiating force for the ignition timer control as originally designed.

As an example, truck manufacturers are applying vacuum control of ignition timing to their 45 trucksfor the purpose of obtaining better economy. Many of these trucks have automatic or other speed governing mechanisms located between the carburetor andthe engine manifold, that operate to close off at high speeds so; as to 50 control the maximum speed attainable. When the governors are operating, the position of the governor valve corresponds to part throttle operation of the truck engine, which transforms that part of the fuel induction passage between 55 the governor valve and the throttle valve to one erno'rvalve.

economy. Though there should be a vacuumcreated advance when the governor throttle is closed, or nearly closedit thus occurs that in- :1 sertion of a" governor in the intake passage eliminate's the vacuum control, and results in the loss of fuel economy.

Itis therefore an object of .the invention to provide an ignition timer control that will func- 5 tion' with equal efficiency, whether the engine speed be controlled by the usual throttle valve,

or control-led'by a' governing valve.

, Another object of the invention is to provide ignition' timer control mechanism that will be 20 effectively operableboth when installed in conjunction with the conventional arrangement of structure providecl'by the equipment manufacturer, and also when the conventional structure is modif ed by additions or modifications that 25 Wouldtend to disturb the ordinary potentials of the fuel induction pipe.

Another object'of the invention is to provide vacuum control of ignition timing for governor equipr'ied' internal combustion motors so as to 30 improve the economy of fuel consumption.

A'further object of the invention is to provide a vacuum control ofignition timing for internal combustionmotors that will not be disturbed -ineffectiveness when a speed governing .35 or other fuel regulating-device is interposed between the usual throttle and the cylinders of the internal'combustion motor.

A further object of the invention is to provide: vacuum control ignition timers as original 40 equipment for internal combustion engines, the efficiency of which'control will not be altered by the-addition of auxiliary devices to the engine intake system. I

Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawing wherein a preferred embodiment of the invention is clearly shown.

The above objects have been accomplished, and the stated problems have been solved, by providing a vacuum take-oil? in the induction pipe posterior to or on the engine side of the usual throttle valve, such as in the carburetor end of the intake manifold, and. thence providing a passage in communication therewith that leads to the usual vacuum motive unit, with passage interrupting means operable through movement of the usual throttle valve, for selectively exposing the motive unit to the vacuum take-off port, and for isolating the motor unit therefrom. The optional interruption of the connecting passage is effectively accomplished by providing one end of the throttle shaft or other relative element with a cross bore, recess or the like of that, at certain positions, is alignable with the said passage, but in other positions is entirely out of communication with the said passage. In one form of construction, when the cross bore is out of communication with the vacuum take-ofi port, it establishes communication between the motive unit and a region of higher pressure, such as outside atmosphere, or in lieu of atmosphere, communi cation is established with carbureted gases in the fuel induction passage anterior to the usual throttle valve.

In the drawing: 1

Fig. 1 is a schematic view, with parts shown in section, illustrating details of the instant invention.

v Fig. 2 is a view in section showing certain modifications of an interruptable passage.

, Fig. 3 is a similar view illustrating modifications. 1

With particular reference to the drawing, III indicates a fuel induction passage of an internal combustion motor, to which there is usually attached, as by bolts or screws, a flange [2 of a carburetor part I4, and in the latter of which there is provided the usual throttle valve I6, which may be in the form of a butterfly valve carried by and rotatable with a shaft I 8 when actuated manually. The shaft I8 extends across the bore 28 of the carburetor part I4, and has its ends journalled in bosses 22, one of which is shown in section in the drawing. Another boss, such as 24, provides a threaded bore 26 from which a passage 28 leads to and ends at the surface of the shaft I8. In the boss 22, and on the opposite side of the shaft I8 from the passage 28, a chamber 30 is provided, from which passage 32 extends to the end face of the flange l2 of the carburetor part, Where it registers with the end of a passage 34 in the wall of the fuel induction pipe I8, and that eventually opens into the passage 36 of the pipe III, at a vacuum takeoff port 38. Thus the passages 28, 32 and 34 will establish unrestricted communication between the threaded bore 26 of the boss 24 and the vacuum take-off port 38 of the fuel induction pipe, were it not for the interruption provided by the shaft I8 intersecting the passage. It is desirable to have complete interruption of this passage when the throttle valve I6 is in substantially closed position such as illustrated in dotted lines in Fig. 1, or during a condition of engine starting or low engine idling speeds. At certain speeds of engine rotation, it is desirable to eifect unrestricted communication between the threaded bore 26 and the vacuum takeoff port 38. This is accomplished by placing in the shaft I8, a cross bore or like passage 40, and so locating it as respects the position of the valve I6 that the passage 48 will line up with the passage 28 and chamber 30 in the before mentioned predetermined throttle position.

Having this organization of parts, an auxiliary device, such as the body 50 of a speed governing mechanism, may be inserted between the carburetor part I4 and the fuel induction pipe I!) the passage 28.

without disturbing the communication between the threaded bore 28 and the vacuum take-off 38, simply by providing in the part 50 a connecting passage 52 that either registers or communicates with the passages 32 and 34. An insertion of that kind is illustrated in Fig. 1, where the part 58 provides a thru bore 54, forming a continuance of the passages 28 and 36, and that is automatically or otherwise valved off by a governor throttle element 56, carried by a shaft 58. If so desired, the passage 52 may have a branch 68 ending in a port 62 in the passage 54 of the part 50.

Communication is made with a vacuum unit or motive element 10 thru a tube or pipe I2 provided with coupling members I4 and I6 threaded into the boss 24 and an equivalent part I8 of the mtive unit, respectively. The said equivalent part has a passage 88 leading to expansion chamber of the motive element all as is the usual and well known construction. It is also known to those experienced in the art that the movable element of the vacuum unit or motive element actuates a link 82 that in this instance has a pivotalconnection at 84 with a breaker plate 86, the latter of which is shiftable within a timer housing 88, that in turn supports a bracket 90 to which the motive element is secured. Shifting of the breaker plate 86 operates to shift angularly a breaker mechanism 94, with respect to a rotating cam 96 operable to periodically move a rubbing block 98 by which opening and closing of cooperable contacts I00 is effected.

As illustrated in Fig. 1, where the passage between the threadedbore 26 and vacuum take-off 38 is interrupted, the circuit breaker or timer mechanismis in the spark retard position, but is adapted to be moved to a spark advanced position when the cross bore 40 is lined up with the passage 28 and chamber 30, for, under those con-.-

ditions, the low pressure existing at the port 38 is thence communicated to the interior of the motive element 10, that causes movement of the link 82 in the direction of the arrow I02, thereby effecting advance of timer operation. That.

function of the motive element will obtain irrespective of whether the passages 32 and 34 be directly connected as in end-to-end relation, or whether they be connected by the interposition of passage 52 when the auxiliary member 50 is inserted in the fuel induction passage.

Under certain conditions it may be desirable, such as upon rather complete deceleration of the motor, to quickly relieve the tension Within the motive element 70 so thatthe ignition timing may be retarded, and that may be accomplished by a relief or bleed passage III! in the boss 22, and so situated as respects the cross bore in the shaft l8 as to communicate with the passage 28 at some prescribed angular position of the throttle shaft I8. Making toward that end, one end of the bore 40 is enlarged or reamed out as at I I 2, or at that end that would communicate with A construction of this kind is illustrated in Fig. 2 where the auxiliary passage I I 6 opens to outside atmosphere.

It may be desirable under the same conditions to relieve the tension within the motive element by switching it to the potential of the car bureted gases in the carburetor part I4, one con-' H8 is directed into the bore 20 of the ca u etor part I4, to end in a port I20. Those passages may all constitute bores or drill holes in the bosses or walls forming the carburetor part I4, with the outside ends of the passages H0, H4, H6 and H8 being closed off by appropriate plugs I22, I24 and I26. Under these conditions, when the throttle valve is closed, or nearly closed, the motive element ID will be connected through the threaded bore 26, and the passages 28, H2, H0, H4, H6, H8 and I20 to the anterior or carburetor side of the throttle valve, and will be completely isolated from the vacuum take-ofi port 38. Full retard of spark timing is thereby effected, since the motive element 10 is now subject to substantially atmospheric pressure existing at the point I20. On the other hand a slight rotation of the shaft I 8 cuts off the relief to the motive element 10 and connects it with the take-off port 38, upon the occurrence of which the desired timer shift is effected, whether the engine speed be controlled by the throttle valve I6 or by the governor valve 56.

While the embodiment of the present invention constitutes a preferred form, it is to be understood that other forms might be adopted, all coming within the scope of the claims which follow.

What is claimed is as follows:

1. In hydro-carbon motors having a fuel induction pipe with a manually controlled throttle valve and a speed controlled governing valve therein and a vacuum unit for altering the time of fuel ignition, the combination comprising means providing a port in the fuel induction pipe posterior to the governing throttle, means including a passage for connecting the vacuum unit with said port, and a rotatable shaft for the throttle intersecting said passage, and providing means for shifting the connection of the vacuum unit from the port to atmospheric pressure while the motor is idling.

2. In a hydro-carbon motor having a fuel induction pipe provided with a speed controlled governing valve and vacuum operated means for altering the time of fuel ignition, the combination comprising, means providing a port to the interior of the induction pipe on the motor side of the speed controlled governing valve, means providing a fluid passage for connecting the vacuum operated means with the port, a rotatable shaft intersecting the passage, and means including a passage in the shaft for opening and closing communication between the port and the vacuum operated means, said shaft with its passage operating alternately to subject the vacuum operated unit to the pressure of the fuel induction pipe on the motor side of the speed controlled governing valve during a predetermined range of throttle opening and to render the vacuum operated unit wholly inactive for throttle openings outside of the predetermined range.

3. The combination set forth in claim 2, wherein means are provided for opening the vacuum operated means to relatively high pressure when it is closed off from communication with the port.

4. In a hydro-carbon motor having a fuel induction pipe provided with an automatic speed governing valve, and vacuum operated means for altering the time of fuel ignition, the combination comprising, means providing a port to the interior of the induction pipe on the motor side of the speed governing valve, means providing a fluid passage for connecting the 'vaccum operated means with the port, and means for interrupting the fluid passage including a shaft intersecting the passage and having an opening therethrough alignable with the passage upon predetermined movement of the shaft, said shaft and opening operating on the one hand to directly connect the vacuum operated means with said port and operating onthe other handto eliminate connection of the vacuum operated means with any port opening into the fuel induction pipe.

5. In hydro-carbon motors having a fuel indiiction pipe with a manually controlled throttle valve and a speed controlled governing valve therein, and a vacuum unit for altering the time of fuel ignition, the combination comprising a vacuum take-off opening into the fuel induction pipe posterior to the governing valve, means connecting the vacuum unit with the take-off, and.

means provided by the manually controlled throttle for controlling the fluid connection in JAMES L. ARTHUR. 

